Balanced slide-valve



(No ModeL) 4 AP F. KEILY. BALANCED SLIDE VALVE.

Patented Jan. 30, 1894.

I JV VEJVTOR wm mssms' flttorney UNITED STATES PATENT OFFICE.

ARTHUR F. KEILY, OF 'MACON, GEORGIA.

BALANCED SLI DE VALVE.

SPECIFICATION forming part of Letters Patent N 0. 513,938, dated January30, 1894.

Application filed April 28, 1393. Serial No. 472,209- (No model.)

To all whom it may concern:

Be it known that I, ARTHUR F. KEILY, a citizen of the United States, anda resident of Macon, in the county of Bibb and State of Georgia, haveinvented certain new and useful Improvements in Balanced Slide-Valves;and I do declare the following to bea full, clear, and exact descriptionof the invention, such as will enable others skilled in the art to whichit appertains to make and use the same,

reference being had to the accompanying.

drawings, and to letters of reference marked thereon, which form a partof this specification.

Figure 1 of the drawings is a vertical longitudinal section of valve andsteam chest. Fig. 2 is a vertical transverse section taken on line a: a;Fig. 3. Fig. 3 is aperspective view of the valve. Figs. 4, 5 and 6 areviews in perspective of the packing strips.

This invention has relation to certain new and useful improvements inbalanced. slide valves, the object being to provide improved means formore perfectly excluding steam from the upper face of the valve, andthereby preventing to a large extent the downward pressure thereon ofthe steam in the chest; and the invention consists in the novelconstruction and combination of parts, all as hereinafter specified andpointed out in the claim.

Referring to the accompanying drawings, the letter A designates the bodyof the valve, which may have any suitable form of exhaust cavitytherein. Upon the upper face of the valve is cast or otherwise secured ablock'B, the area of the upper surface of which is somewhat less thanthe area of the face of the valve. Said block is cut away at its endportions to form the vertical lugs O, O, of less transverse width thanthe body of the block, and separated each therefrom by atransversegroove or cavity 0., having true faces or walls. Formed in the bodyportion B of said block or upper portion of the valve, one near eachlateral edge are longitudinal grooves 19, b, having true faces or walls,and extending the entire'lengthof the said block, or upper portion ofthe valve.

F, F, and G, G, designate the packing strips which are placed in thegrooves a, a, and b, b.

F, vF, designate the longitudinal strips, and G, G, the transversestrips. The longitudinal strips F, F, are of such length as to just fitbetween the inner faces of the transverse strips G, G, the latter beingextended laterally beyond the strips F, F, and terminating flush withthe edge of the portion B of the valve.

The strips F, F, are cut away at their lower portions, forming thechambers c, c, and the end legs or lugs f, f, upon which the strips seatwhen resting upon the bottom of the grooves, the end strips beingsimilarly cut away, forming passages'g, g, at each side of the lugs C,0, through which steam may enter underneath the strips F, F.

The outer faces of the strips G, G, are recessed at h, h, to partiallyreceive the lugs O, G, and in a cavity '5 of said recessed portion isseated a spring H. Said spring mav be of semi-elliptical or other form,and bear against the inner faces of the lugs O, C. The outer faces ofthe longitudinal strips F, F, are also recessed at z', 2', to form seatsfor similar springs H, which bear against the outer walls of thegrooves.

The upper faces of the packing strips, which should bepreferably true,are designed to bear against the cover of a steam chest, or against abalance plate K, Within said chest, in a steam tight manner, so as toexclude all steam from within the area inclosed by said strips, thusreducing the downward pressure on the valve sufficiently to balance itagainst the pressure of the exhaust steam at the under side. The springsH serve to press the four strips closely together at their meetingfaces, so that no steam can enter at the corners. The tension of thesprings is also sufficient to press the packing strips against the Valvewith sufficient force to maintain them in their raised position aftersteam is cut off, so that the usual bottom springs may be dispensedwith,and steam be prevented from getting above the strips when it is againturned on. Said springs also serve to take up the wear of the saidstrip, and thereby prevent the latter from becoming loose. Stripsemployed without these springs soon become worn to such an extent thatthey become useless and have to be renewed owing to the fact that whenso worn they admit steam upon all sides of them and their action isprevented. In the present device, inasmuch as close joints aremaintained when the steam is cut on as well as when it is on, it is notpossible for steam to get between them. With the springs, one set ofstrips will last until they become worn down from the top. The use ofthe springs also enables the strips to be fitted with less work andcare, it not being necessary to fit the lateral faces with as muchaccuracy, inasmuch as the springs take up any play or looseness theremay be. The springs further serve to prevent the strips from breaking,and pieces thereof falling into the cylinder.

Having thus described my invention, what I claim, and desire to secureby Letters latent, is-- In a balanced slide valve, the combination withthe valve body, having the longitudinal grooves b, b, and the transversegrooves or seats a, of the transverse packing strips G, G seated in saidgrooves or seats a, a, the longitudinal packing strips F, F seated inthe grooves b, b, and a spring bearing against the outer face of each ofsaid strips F, F and G, G, and pressing them against each other andagainst the valve whereby a tight joint is maintained between the jointsof said strips and they are held up when steam is out 01?, substantiallyas specified.

In testimony whereof I afiix my signature in presence of two witnesses.

A. F. KEILY.

Witnesses:

DUNCAN SMITH, L. W. HOLLINGSWORTH.

